Optical shaping apparatus and optical shaping process

Abstract

The invention provides an optical shaping apparatus comprising a stage 1 having a light transmitting portion 11 , an irradiator 4 disposed below the stage 1 , a table 3 disposed above the stage 1 and having a resin supply hole provided with an opening in a rear surface thereof, a lift mechanism 2 for driving the table 2 upward and downward, an optical shaping control unit 8 for controlling the operation of the lift mechanism 2 and the irradiator 4 , and a resin supply tank 5 for supplying an uncured resin to the resin supply hole of the table 3 . The uncured resin is filled into a space between the table 3 or a cured resin layer formed on the rear surface of the table 3 and the stage 1 to form an uncured resin layer of predetermined thickness, and the resin layer is irradiated with light over a region thereof in conformity with contour line data. The apparatus is shortened in shaping time, simplified in construction and compacted.

What is claimed is:  
     
         1 . An optical shaping apparatus for producing an optically shaped article of predetermined three-dimensional shape by irradiating layers of photosetting resin with light based on contour line data representing the three-dimensional shape of the article to cure the resin layers as superposed, the optical shaping apparatus being characterized in that the apparatus comprises: 
 a stage ( 1 ) permitting transmission of light through at least a central portion ( 11 ) thereof,    an irradiator ( 4 ) disposed below the stage ( 1 ) and directed toward the light transmitting portion ( 11 ) of the stage ( 1 ) for irradiating with light a region in conformity with contour line data representing the three-dimensional shape of an article to be optically shaped,    a table ( 3 ) disposed above the stage ( 1 ) and having a resin supply hole ( 31 ) provided with an opening in a rear surface thereof,    a lift mechanism ( 2 ) for vertically driving one of the stage ( 1 ) and the table ( 3 ) toward or away from the other, an optical shaping control unit ( 8 ) for controlling the operation of the lift mechanism ( 2 ) and the irradiator ( 4 ), and    a resin feeder for supplying uncured resin to the resin supply hole ( 31 ) of the table ( 3 ),    the apparatus being operable to superpose cured resin layers ( 62 ) to obtain a shaped article ( 6 ) comprising superposed layers and having a predetermined three-dimensional shape by repeating the steps of filling the uncured resin ( 64 ) into a space between the table ( 3 ) or a cured resin layer ( 62 ) formed on the rear surface of the table ( 3 ) and the stage ( 1 ), forming an uncured resin layer ( 65 ) of predetermined thickness, and irradiating the resin layer ( 65 ) over an entire region thereof in conformity with the contour line data except a central region in register with the resin supply hole ( 31 ).    
     
     
         2 . An optical shaping apparatus according to    claim 1    wherein the optical shaping control unit ( 8 ) repeatedly executes the step of moving the table ( 3 ) toward the stage ( 1 ) relative thereto to bring the table ( 3 ) or the cured resin layer ( 62 ) formed on the rear surface of the table ( 3 ) into contact with the stage ( 1 ), thereafter moving the table ( 3 ) away from the stage ( 1 ) relative thereto and filling the uncured resin ( 64 ) into a space between the table ( 3 ) or the cured resin layer ( 62 ) formed on the rear surface of the table ( 3 ) and the stage ( 1 ), the step of thereafter moving the table ( 3 ) toward the stage ( 1 ) relative thereto to compress the uncured resin ( 64 ) into an uncured resin layer ( 65 ) having a predetermined thickness, the step of determining a region over which the uncured resin layer ( 65 ) is to be irradiated with light, in accordance with the contour line data, and the step of irradiating the determined region with light.  
     
     
         3 . An optical shaping apparatus according to    claim 2    wherein in determining the region of irradiation by the optical shaping control unit ( 8 ) for a plurality of resin layers constituting the article to be shaped, the region of irradiation for each of resin layers including the first layer in contact with the rear surface of the table ( 3 ) is determined by excluding the central region from the entire region conforming to the contour line data, and the irradiation region for the final layer remotest from the table ( 3 ) is determined without excluding the central region from the entire region conforming to the contour line data.  
     
     
         4 . An optical shaping process for producing an optically shaped article of predetermined three-dimensional shape by irradiating layers of photosetting resin with light based on contour line data representing the three-dimensional shape of the article to cure the resin layers as superposed, the optical shaping process being characterized by repeatedly executing: 
 the step of moving a table ( 3 ) toward a stage ( 1 ) relative thereto to bring the table ( 3 ) or a cured resin layer ( 62 ) formed on a rear surface of the table ( 3 ) into contact with the stage ( 1 ), thereafter moving the table ( 3 ) away from the stage ( 1 ) relative thereto and filling an uncured resin ( 64 ) into a space between the table ( 3 ) or the cured resin layer ( 62 ) formed on the rear surface of the table ( 3 ) and the stage ( 1 ),    the step of thereafter moving the table ( 3 ) toward the stage ( 1 ) relative thereto to compress the uncured resin ( 64 ) into an uncured resin layer ( 65 ) having a predetermined thickness,    the step of determining a region over which the uncured resin layer ( 65 ) is to be irradiated with light, in accordance with the contour line data,    the step of irradiating the determined region with light, and    the step of moving the table ( 3 ) away from the stage ( 1 ) relative thereto to separate a cured resin layer ( 61 ) formed by irradiation from the surface of the stage ( 1 ).    
     
     
         5 . An optical shaping apparatus for producing an optically shaped article of predetermined three-dimensional shape by irradiating layers of photosetting resin with light based on contour line data representing the sectional shape of the article to cure the resin layers as superposed, the optical shaping apparatus being characterized in that the apparatus comprises: 
 a stage ( 1 ) having a light transmitting portion ( 12 ) in the form of a flat plate and so supported as to be drivable along a horizontal plane,    a horizontal drive mechanism for driving the stage ( 1 ) along the horizontal plane,    a resin feeder for supplying an uncured photosetting resin to a surface of the light transmitting portion ( 12 ) of the stage ( 1 ),    an irradiator ( 4 ) disposed below the stage ( 1 ) and directed toward a rear surface of the stage ( 1 ) for irradiating a region in conformity with the contour line data with light,    a table ( 3 ) disposed above the stage ( 1 ) and opposed to the irradiator ( 4 ), the table being movable upward and downward, a lift drive mechanism ( 2 ) for driving the table ( 3 ) upward and downward, and    an optical shaping control unit ( 8 ) for controlling the operation of the horizontal drive mechanism, the lift drive mechanism ( 2 ) and the irradiator ( 4 ).    
     
     
         6 . An optical shaping apparatus according to    claim 5    wherein the optical shaping control unit ( 8 ) repeatedly executes first control for driving the stage ( 1 ) with the uncured resin ( 62 ) supplied to the light transmitting portion ( 12 ) of the stage ( 1 ) to transport the uncured resin ( 62 ) to the irradiating position, second control for lowering the table ( 3 ) to compress the uncured resin ( 62 ) with the table ( 3 ) or a cured resin layer ( 61 ) adhering to a rear surface of the table ( 3 ), third control for irradiating the resulting uncured resin layer ( 64 ) formed on the stage ( 1 ) with light, and fourth control for raising the table ( 3 ) to separate the cured resin layer ( 61 ) formed by irradiation from the surface of the stage ( 1 ).  
     
     
         7 . An optical shaping apparatus according to    claim 5    wherein the resin feeder comprises a recoater ( 7 ) for supplying the uncured resin ( 62 ) to the surface of the light transmitting portion ( 12 ) of the stage ( 1 ) and leveling the uncured resin ( 62 ) to an approximately uniform thickness at the same time.  
     
     
         8 . An optical shaping apparatus according to    claim 7    wherein the uncured resin layer to be formed by the recoater ( 7 ) has a thickness at least twice the pitch of the superposed layers to be formed.  
     
     
         9 . An optical shaping apparatus according to    claim 5    wherein the stage ( 1 ) is so supported as to be rotatable in a horizontal plane, and the horizontal drive mechanism comprises a motor ( 13 ) for drivingly rotating the stage ( 1 ) in one direction along a horizontal plane.  
     
     
         10 . An optical shaping apparatus according to    claim 9    wherein the optical shaping control unit ( 8 ) alters the angle of rotation of the stage ( 1 ) in accordance with the size of the region to be irradiated with light by the irradiator ( 4 ).  
     
     
         11 . An optical shaping process for producing an optically shaped article of predetermined three-dimensional shape by irradiating layers of photosetting resin with light based on contour line data representing the sectional shape of the article to cure the resin layers as superposed, the optical shaping process being characterized by repeatedly executing: 
 the step of driving a stage ( 1 ) in a horizontal direction with the uncured resin ( 62 ) supplied to a light transmitting portion ( 12 ) of the stage ( 1 ) to transport the uncured resin ( 62 ) to an irradiating position,    the step of lowering a table ( 3 ) to compress the uncured resin ( 62 ) with the table ( 3 ) or a cured resin layer ( 61 ) adhering to a rear surface of the table ( 3 ),    the step of irradiating the resulting uncured resin layer ( 64 ) on the stage ( 1 ) with light, and    the step of raising the table ( 3 ) to separate the cured resin layer ( 61 ) formed by irradiation from a surface of the stage ( 1 ).